pitrou commented on code in PR #1000: URL: https://github.com/apache/parquet-mr/pull/1000#discussion_r997964441
########## parquet-hadoop/src/main/java/org/apache/parquet/hadoop/codec/Lz4RawCodec.java: ########## @@ -0,0 +1,112 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.parquet.hadoop.codec; + +import org.apache.hadoop.conf.Configurable; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.io.compress.CompressionCodec; +import org.apache.hadoop.io.compress.CompressionInputStream; +import org.apache.hadoop.io.compress.CompressionOutputStream; +import org.apache.hadoop.io.compress.Compressor; +import org.apache.hadoop.io.compress.Decompressor; + +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; + +/** + * Lz4 raw compression codec for Parquet. This codec type has been introduced + * into the parquet format since version 2.9.0. It differs from the Lz4Codec + * shipped with Apache Hadoop by removing the light frame header which includes + * 4 byte for uncompressed length and 4 byte for compressed length. In the + * Apache Arrow implementation, these two Lz4 codecs are recognized as LZ4_RAW + * and LZ4_HADOOP to minimize the confusion at its best. Please check the link + * below for reference. + * https://github.com/apache/parquet-format/blob/master/Compression.md + */ +public class Lz4RawCodec implements Configurable, CompressionCodec { + + private Configuration conf; + + // Hadoop config for how big to make intermediate buffers. + public static final String BUFFER_SIZE_CONFIG = "io.file.buffer.size"; + + private static final int DEFAULT_BUFFER_SIZE_CONFIG = 4 * 1024; Review Comment: Can you explain what this is used for? Also, 4 kiB seems extremely small for compression purposes. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: dev-unsubscr...@parquet.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
